The oxygen mobility of Bi_xCe_1-x (x = 0, 0.1, 0.2, 0.3, 1) has been experimentally and theoretically investigated. The catalysts were synthesized by a simple co-precipitation method and used for soot combustion. As shown in Raman results, Bi_0.2Ce_0.8 has the largest amount of oxygen vacancies. The interaction of the Bi-Ce system is also presented in the outcomes of XPS, H₂-TPR and O₂-TPD, as well as the increased active oxygen species caused by the weakening of the metal-oxygen bond resulting from the oxygen mobility. Additionally, the electronic transfer between the Bi and Ce and the elongation of the Ce-O reported in the DFT studies support the synergism of Bi-Ce and the tuned mobility of oxygen. Further, the decrease of formation energy of oxygen vacancies presented in Bi_0.2Ce_0.8 in agreement with the experimental results. Moreover, the optimal adsorption capacity demonstrates excellent activity. Finally, we have well verified our previous proof that Bi_0.2Ce_0.8, which has a higher oxygen ion mobility, has the best catalytic performance under tight and loose conditions. Our work deepens the understanding of oxygen mobility over Bi-doped CeO₂ and provides a strategy to promote the catalytic activity by tuning the oxygen mobility.

Bi _x Ce _1-x（x = 0、0.1、0.2、0.3、1）的氧迁移率已通过实验和理论研究。该催化剂通过简单的共沉淀法合成并用于烟灰燃烧。如拉曼结果所示，Bi _0.2 Ce _0.8具有最大的氧空位。XPS，H ₂ -TPR和O ₂的结果也显示了Bi-Ce系统的相互作用。-TPD，以及由氧迁移率引起的金属-氧键减弱导致的活性氧种类增加。此外，DFT研究中报道的Bi与Ce之间的电子转移以及Ce-O的延伸支持了Bi-Ce的协同作用和调节的氧迁移率。此外，Bi _0.2 Ce _0.8中氧空位形成能的降低与实验结果一致。而且，最佳的吸附容量显示出优异的活性。最后，我们已经很好地验证了我们先前的证明Bi _0.2 Ce _0.8具有较高的氧离子迁移率，在严密和宽松的条件下具有最佳的催化性能。我们的工作加深了对Bi掺杂CeO ₂上氧迁移率的理解，并提供了一种通过调节氧迁移率来提高催化活性的策略。